We used to think that the left brain controlled your thinking and that the right brain controlled your heart. But neuroscientists have learned that it’s a lot more complicated.

In 2007, an influential paper in the journal Behavioral and Brain Functions found that while most of us process emotions through the right hemisphere of the brain, about 35% of people — especially victims of trauma — process their hurt and anger through their left brain, where logic and language sit. That may be because they had worked so hard to explain, logically, why they were suffering. But pushing emotions through the left brain taxed it: these people performed significantly worse on memory tests.

Now a new paper — out in the September issue of The Journal of Nervous and Mental Disease — further complicates the picture with a surprising finding: whether you are right-handed, left-handed or ambidextrous (which the authors call, rather delightfully, “inconsistently handed”) seems to be an important clue in understanding how you use your brain to process emotions. (More on Time.com: Diagnosing Postpartum Depression with a Brain Scan)

It’s been known for some time that lefties and the ambidextrous are more prone to negative emotions. The new study shows that they also have a greater imbalance in activity between the left and right brains when they process emotions. Of course, you can’t be sure which comes first: maybe angry people are more out of balance, or maybe the inability to find equilibrium makes you angry. As for the left-handed: maybe they’re more angry because the world is designed for the right-handed majority.

The study also used an interesting method to find that angry people are, literally, hot-headed: the authors of the paper — led by Ruth Propper, a psychology professor at Merrimack College in Massachusetts — measured brain-hemisphere activation with a relatively old method called tympanic membrane temperature, which is essentially how hot it is in your inner ear. If you get angry a lot, your head tends to be warmer.

One problem is that the study was small — just 55 undergraduates participated (they were paid $20 each for having to endure ear-temperature tests and psychological questioning). Also, The Journal of Nervous and Mental Disease, while peer-reviewed, is one of less-respected psychology journals. Still, I like the study just because it explains that when you get hot under the collar, you are actually hot under the collar.